Day 7 - Continued

I went to the gym tonight. It was packed. All of the treadmills were being used so I got on the stair climber for 15 minutes. Luckily a treadmill became free and I hopped right on it. I walked for 3 minutes and then kicked it up to start jogging for 4. And then the burn set in. Like this morning, my calf muscles were on FIRE! I could only take it for two minutes and then I had to slow it back down. The burn continued while I was walking. So after 15 minutes, I hopped off the Tread and got on the bike. I don't know what the heck is going on. I didn't have this problem Saturday. What's the deal? I need to find out because I'm not going to make any progress if this continues. *sigh*